2 * linux/fs/ext2/super.c
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
11 * linux/fs/minix/inode.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
15 * Big-endian to little-endian byte-swapping/bitmaps by
16 * David S. Miller (davem@caip.rutgers.edu), 1995
19 #include <linux/module.h>
20 #include <linux/string.h>
22 #include <linux/slab.h>
23 #include <linux/init.h>
24 #include <linux/blkdev.h>
25 #include <linux/parser.h>
26 #include <linux/random.h>
27 #include <linux/buffer_head.h>
28 #include <linux/exportfs.h>
29 #include <linux/vfs.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <linux/log2.h>
33 #include <linux/quotaops.h>
34 #include <asm/uaccess.h>
40 static void ext2_sync_super(struct super_block *sb,
41 struct ext2_super_block *es, int wait);
42 static int ext2_remount (struct super_block * sb, int * flags, char * data);
43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
44 static int ext2_sync_fs(struct super_block *sb, int wait);
46 void ext2_error (struct super_block * sb, const char * function,
47 const char * fmt, ...)
50 struct ext2_sb_info *sbi = EXT2_SB(sb);
51 struct ext2_super_block *es = sbi->s_es;
53 if (!(sb->s_flags & MS_RDONLY)) {
54 spin_lock(&sbi->s_lock);
55 sbi->s_mount_state |= EXT2_ERROR_FS;
56 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
57 spin_unlock(&sbi->s_lock);
58 ext2_sync_super(sb, es, 1);
62 printk(KERN_CRIT "EXT2-fs (%s): error: %s: ", sb->s_id, function);
67 if (test_opt(sb, ERRORS_PANIC))
68 panic("EXT2-fs: panic from previous error\n");
69 if (test_opt(sb, ERRORS_RO)) {
70 ext2_msg(sb, KERN_CRIT,
71 "error: remounting filesystem read-only");
72 sb->s_flags |= MS_RDONLY;
76 void ext2_msg(struct super_block *sb, const char *prefix,
82 printk("%sEXT2-fs (%s): ", prefix, sb->s_id);
89 * This must be called with sbi->s_lock held.
91 void ext2_update_dynamic_rev(struct super_block *sb)
93 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
95 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
98 ext2_msg(sb, KERN_WARNING,
99 "warning: updating to rev %d because of "
100 "new feature flag, running e2fsck is recommended",
103 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
104 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
105 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
106 /* leave es->s_feature_*compat flags alone */
107 /* es->s_uuid will be set by e2fsck if empty */
110 * The rest of the superblock fields should be zero, and if not it
111 * means they are likely already in use, so leave them alone. We
112 * can leave it up to e2fsck to clean up any inconsistencies there.
116 static void ext2_put_super (struct super_block * sb)
120 struct ext2_sb_info *sbi = EXT2_SB(sb);
123 ext2_write_super(sb);
125 ext2_xattr_put_super(sb);
126 if (!(sb->s_flags & MS_RDONLY)) {
127 struct ext2_super_block *es = sbi->s_es;
129 spin_lock(&sbi->s_lock);
130 es->s_state = cpu_to_le16(sbi->s_mount_state);
131 spin_unlock(&sbi->s_lock);
132 ext2_sync_super(sb, es, 1);
134 db_count = sbi->s_gdb_count;
135 for (i = 0; i < db_count; i++)
136 if (sbi->s_group_desc[i])
137 brelse (sbi->s_group_desc[i]);
138 kfree(sbi->s_group_desc);
140 percpu_counter_destroy(&sbi->s_freeblocks_counter);
141 percpu_counter_destroy(&sbi->s_freeinodes_counter);
142 percpu_counter_destroy(&sbi->s_dirs_counter);
144 sb->s_fs_info = NULL;
145 kfree(sbi->s_blockgroup_lock);
149 static struct kmem_cache * ext2_inode_cachep;
151 static struct inode *ext2_alloc_inode(struct super_block *sb)
153 struct ext2_inode_info *ei;
154 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
157 ei->i_block_alloc_info = NULL;
158 ei->vfs_inode.i_version = 1;
159 return &ei->vfs_inode;
162 static void ext2_destroy_inode(struct inode *inode)
164 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
167 static void init_once(void *foo)
169 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
171 rwlock_init(&ei->i_meta_lock);
172 #ifdef CONFIG_EXT2_FS_XATTR
173 init_rwsem(&ei->xattr_sem);
175 mutex_init(&ei->truncate_mutex);
176 inode_init_once(&ei->vfs_inode);
179 static int init_inodecache(void)
181 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
182 sizeof(struct ext2_inode_info),
183 0, (SLAB_RECLAIM_ACCOUNT|
186 if (ext2_inode_cachep == NULL)
191 static void destroy_inodecache(void)
193 kmem_cache_destroy(ext2_inode_cachep);
196 static void ext2_clear_inode(struct inode *inode)
198 struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
201 ext2_discard_reservation(inode);
202 EXT2_I(inode)->i_block_alloc_info = NULL;
207 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
209 struct super_block *sb = vfs->mnt_sb;
210 struct ext2_sb_info *sbi = EXT2_SB(sb);
211 struct ext2_super_block *es = sbi->s_es;
212 unsigned long def_mount_opts;
214 spin_lock(&sbi->s_lock);
215 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
217 if (sbi->s_sb_block != 1)
218 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
219 if (test_opt(sb, MINIX_DF))
220 seq_puts(seq, ",minixdf");
221 if (test_opt(sb, GRPID))
222 seq_puts(seq, ",grpid");
223 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
224 seq_puts(seq, ",nogrpid");
225 if (sbi->s_resuid != EXT2_DEF_RESUID ||
226 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
227 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
229 if (sbi->s_resgid != EXT2_DEF_RESGID ||
230 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
231 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
233 if (test_opt(sb, ERRORS_RO)) {
234 int def_errors = le16_to_cpu(es->s_errors);
236 if (def_errors == EXT2_ERRORS_PANIC ||
237 def_errors == EXT2_ERRORS_CONTINUE) {
238 seq_puts(seq, ",errors=remount-ro");
241 if (test_opt(sb, ERRORS_CONT))
242 seq_puts(seq, ",errors=continue");
243 if (test_opt(sb, ERRORS_PANIC))
244 seq_puts(seq, ",errors=panic");
245 if (test_opt(sb, NO_UID32))
246 seq_puts(seq, ",nouid32");
247 if (test_opt(sb, DEBUG))
248 seq_puts(seq, ",debug");
249 if (test_opt(sb, OLDALLOC))
250 seq_puts(seq, ",oldalloc");
252 #ifdef CONFIG_EXT2_FS_XATTR
253 if (test_opt(sb, XATTR_USER))
254 seq_puts(seq, ",user_xattr");
255 if (!test_opt(sb, XATTR_USER) &&
256 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
257 seq_puts(seq, ",nouser_xattr");
261 #ifdef CONFIG_EXT2_FS_POSIX_ACL
262 if (test_opt(sb, POSIX_ACL))
263 seq_puts(seq, ",acl");
264 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
265 seq_puts(seq, ",noacl");
268 if (test_opt(sb, NOBH))
269 seq_puts(seq, ",nobh");
271 #if defined(CONFIG_QUOTA)
272 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
273 seq_puts(seq, ",usrquota");
275 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
276 seq_puts(seq, ",grpquota");
279 #if defined(CONFIG_EXT2_FS_XIP)
280 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
281 seq_puts(seq, ",xip");
284 if (!test_opt(sb, RESERVATION))
285 seq_puts(seq, ",noreservation");
287 spin_unlock(&sbi->s_lock);
292 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
293 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
296 static const struct super_operations ext2_sops = {
297 .alloc_inode = ext2_alloc_inode,
298 .destroy_inode = ext2_destroy_inode,
299 .write_inode = ext2_write_inode,
300 .delete_inode = ext2_delete_inode,
301 .put_super = ext2_put_super,
302 .write_super = ext2_write_super,
303 .sync_fs = ext2_sync_fs,
304 .statfs = ext2_statfs,
305 .remount_fs = ext2_remount,
306 .clear_inode = ext2_clear_inode,
307 .show_options = ext2_show_options,
309 .quota_read = ext2_quota_read,
310 .quota_write = ext2_quota_write,
314 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
315 u64 ino, u32 generation)
319 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
320 return ERR_PTR(-ESTALE);
321 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
322 return ERR_PTR(-ESTALE);
324 /* iget isn't really right if the inode is currently unallocated!!
325 * ext2_read_inode currently does appropriate checks, but
326 * it might be "neater" to call ext2_get_inode first and check
327 * if the inode is valid.....
329 inode = ext2_iget(sb, ino);
331 return ERR_CAST(inode);
332 if (generation && inode->i_generation != generation) {
333 /* we didn't find the right inode.. */
335 return ERR_PTR(-ESTALE);
340 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
341 int fh_len, int fh_type)
343 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
347 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
348 int fh_len, int fh_type)
350 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
354 /* Yes, most of these are left as NULL!!
355 * A NULL value implies the default, which works with ext2-like file
356 * systems, but can be improved upon.
357 * Currently only get_parent is required.
359 static const struct export_operations ext2_export_ops = {
360 .fh_to_dentry = ext2_fh_to_dentry,
361 .fh_to_parent = ext2_fh_to_parent,
362 .get_parent = ext2_get_parent,
365 static unsigned long get_sb_block(void **data)
367 unsigned long sb_block;
368 char *options = (char *) *data;
370 if (!options || strncmp(options, "sb=", 3) != 0)
371 return 1; /* Default location */
373 sb_block = simple_strtoul(options, &options, 0);
374 if (*options && *options != ',') {
375 printk("EXT2-fs: Invalid sb specification: %s\n",
381 *data = (void *) options;
386 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
387 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
388 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
389 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
390 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
391 Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
394 static const match_table_t tokens = {
395 {Opt_bsd_df, "bsddf"},
396 {Opt_minix_df, "minixdf"},
397 {Opt_grpid, "grpid"},
398 {Opt_grpid, "bsdgroups"},
399 {Opt_nogrpid, "nogrpid"},
400 {Opt_nogrpid, "sysvgroups"},
401 {Opt_resgid, "resgid=%u"},
402 {Opt_resuid, "resuid=%u"},
404 {Opt_err_cont, "errors=continue"},
405 {Opt_err_panic, "errors=panic"},
406 {Opt_err_ro, "errors=remount-ro"},
407 {Opt_nouid32, "nouid32"},
408 {Opt_nocheck, "check=none"},
409 {Opt_nocheck, "nocheck"},
410 {Opt_debug, "debug"},
411 {Opt_oldalloc, "oldalloc"},
412 {Opt_orlov, "orlov"},
414 {Opt_user_xattr, "user_xattr"},
415 {Opt_nouser_xattr, "nouser_xattr"},
417 {Opt_noacl, "noacl"},
419 {Opt_grpquota, "grpquota"},
420 {Opt_ignore, "noquota"},
421 {Opt_quota, "quota"},
422 {Opt_usrquota, "usrquota"},
423 {Opt_reservation, "reservation"},
424 {Opt_noreservation, "noreservation"},
428 static int parse_options(char *options, struct super_block *sb)
431 struct ext2_sb_info *sbi = EXT2_SB(sb);
432 substring_t args[MAX_OPT_ARGS];
438 while ((p = strsep (&options, ",")) != NULL) {
443 token = match_token(p, tokens, args);
446 clear_opt (sbi->s_mount_opt, MINIX_DF);
449 set_opt (sbi->s_mount_opt, MINIX_DF);
452 set_opt (sbi->s_mount_opt, GRPID);
455 clear_opt (sbi->s_mount_opt, GRPID);
458 if (match_int(&args[0], &option))
460 sbi->s_resuid = option;
463 if (match_int(&args[0], &option))
465 sbi->s_resgid = option;
468 /* handled by get_sb_block() instead of here */
469 /* *sb_block = match_int(&args[0]); */
472 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
473 clear_opt (sbi->s_mount_opt, ERRORS_RO);
474 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
477 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
478 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
479 set_opt (sbi->s_mount_opt, ERRORS_RO);
482 clear_opt (sbi->s_mount_opt, ERRORS_RO);
483 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
484 set_opt (sbi->s_mount_opt, ERRORS_CONT);
487 set_opt (sbi->s_mount_opt, NO_UID32);
490 clear_opt (sbi->s_mount_opt, CHECK);
493 set_opt (sbi->s_mount_opt, DEBUG);
496 set_opt (sbi->s_mount_opt, OLDALLOC);
499 clear_opt (sbi->s_mount_opt, OLDALLOC);
502 set_opt (sbi->s_mount_opt, NOBH);
504 #ifdef CONFIG_EXT2_FS_XATTR
506 set_opt (sbi->s_mount_opt, XATTR_USER);
508 case Opt_nouser_xattr:
509 clear_opt (sbi->s_mount_opt, XATTR_USER);
513 case Opt_nouser_xattr:
514 ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
518 #ifdef CONFIG_EXT2_FS_POSIX_ACL
520 set_opt(sbi->s_mount_opt, POSIX_ACL);
523 clear_opt(sbi->s_mount_opt, POSIX_ACL);
528 ext2_msg(sb, KERN_INFO,
529 "(no)acl options not supported");
533 #ifdef CONFIG_EXT2_FS_XIP
534 set_opt (sbi->s_mount_opt, XIP);
536 ext2_msg(sb, KERN_INFO, "xip option not supported");
540 #if defined(CONFIG_QUOTA)
543 set_opt(sbi->s_mount_opt, USRQUOTA);
547 set_opt(sbi->s_mount_opt, GRPQUOTA);
553 ext2_msg(sb, KERN_INFO,
554 "quota operations not supported");
558 case Opt_reservation:
559 set_opt(sbi->s_mount_opt, RESERVATION);
560 ext2_msg(sb, KERN_INFO, "reservations ON");
562 case Opt_noreservation:
563 clear_opt(sbi->s_mount_opt, RESERVATION);
564 ext2_msg(sb, KERN_INFO, "reservations OFF");
575 static int ext2_setup_super (struct super_block * sb,
576 struct ext2_super_block * es,
580 struct ext2_sb_info *sbi = EXT2_SB(sb);
582 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
583 ext2_msg(sb, KERN_ERR,
584 "error: revision level too high, "
585 "forcing read-only mode");
590 if (!(sbi->s_mount_state & EXT2_VALID_FS))
591 ext2_msg(sb, KERN_WARNING,
592 "warning: mounting unchecked fs, "
593 "running e2fsck is recommended");
594 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
595 ext2_msg(sb, KERN_WARNING,
596 "warning: mounting fs with errors, "
597 "running e2fsck is recommended");
598 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
599 le16_to_cpu(es->s_mnt_count) >=
600 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
601 ext2_msg(sb, KERN_WARNING,
602 "warning: maximal mount count reached, "
603 "running e2fsck is recommended");
604 else if (le32_to_cpu(es->s_checkinterval) &&
605 (le32_to_cpu(es->s_lastcheck) +
606 le32_to_cpu(es->s_checkinterval) <= get_seconds()))
607 ext2_msg(sb, KERN_WARNING,
608 "warning: checktime reached, "
609 "running e2fsck is recommended");
610 if (!le16_to_cpu(es->s_max_mnt_count))
611 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
612 le16_add_cpu(&es->s_mnt_count, 1);
613 if (test_opt (sb, DEBUG))
614 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
615 "bpg=%lu, ipg=%lu, mo=%04lx]",
616 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
619 EXT2_BLOCKS_PER_GROUP(sb),
620 EXT2_INODES_PER_GROUP(sb),
625 static int ext2_check_descriptors(struct super_block *sb)
628 struct ext2_sb_info *sbi = EXT2_SB(sb);
630 ext2_debug ("Checking group descriptors");
632 for (i = 0; i < sbi->s_groups_count; i++) {
633 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
634 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
635 ext2_fsblk_t last_block;
637 if (i == sbi->s_groups_count - 1)
638 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
640 last_block = first_block +
641 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
643 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
644 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
646 ext2_error (sb, "ext2_check_descriptors",
647 "Block bitmap for group %d"
648 " not in group (block %lu)!",
649 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
652 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
653 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
655 ext2_error (sb, "ext2_check_descriptors",
656 "Inode bitmap for group %d"
657 " not in group (block %lu)!",
658 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
661 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
662 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
665 ext2_error (sb, "ext2_check_descriptors",
666 "Inode table for group %d"
667 " not in group (block %lu)!",
668 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
676 * Maximal file size. There is a direct, and {,double-,triple-}indirect
677 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
678 * We need to be 1 filesystem block less than the 2^32 sector limit.
680 static loff_t ext2_max_size(int bits)
682 loff_t res = EXT2_NDIR_BLOCKS;
686 /* This is calculated to be the largest file size for a
687 * dense, file such that the total number of
688 * sectors in the file, including data and all indirect blocks,
689 * does not exceed 2^32 -1
690 * __u32 i_blocks representing the total number of
691 * 512 bytes blocks of the file
693 upper_limit = (1LL << 32) - 1;
695 /* total blocks in file system block size */
696 upper_limit >>= (bits - 9);
699 /* indirect blocks */
701 /* double indirect blocks */
702 meta_blocks += 1 + (1LL << (bits-2));
703 /* tripple indirect blocks */
704 meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
706 upper_limit -= meta_blocks;
707 upper_limit <<= bits;
709 res += 1LL << (bits-2);
710 res += 1LL << (2*(bits-2));
711 res += 1LL << (3*(bits-2));
713 if (res > upper_limit)
716 if (res > MAX_LFS_FILESIZE)
717 res = MAX_LFS_FILESIZE;
722 static unsigned long descriptor_loc(struct super_block *sb,
723 unsigned long logic_sb_block,
726 struct ext2_sb_info *sbi = EXT2_SB(sb);
727 unsigned long bg, first_meta_bg;
730 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
732 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
734 return (logic_sb_block + nr + 1);
735 bg = sbi->s_desc_per_block * nr;
736 if (ext2_bg_has_super(sb, bg))
739 return ext2_group_first_block_no(sb, bg) + has_super;
742 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
744 struct buffer_head * bh;
745 struct ext2_sb_info * sbi;
746 struct ext2_super_block * es;
749 unsigned long sb_block = get_sb_block(&data);
750 unsigned long logic_sb_block;
751 unsigned long offset = 0;
752 unsigned long def_mount_opts;
754 int blocksize = BLOCK_SIZE;
760 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
764 sbi->s_blockgroup_lock =
765 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
766 if (!sbi->s_blockgroup_lock) {
771 sbi->s_sb_block = sb_block;
773 spin_lock_init(&sbi->s_lock);
776 * See what the current blocksize for the device is, and
777 * use that as the blocksize. Otherwise (or if the blocksize
778 * is smaller than the default) use the default.
779 * This is important for devices that have a hardware
780 * sectorsize that is larger than the default.
782 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
784 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
789 * If the superblock doesn't start on a hardware sector boundary,
790 * calculate the offset.
792 if (blocksize != BLOCK_SIZE) {
793 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
794 offset = (sb_block*BLOCK_SIZE) % blocksize;
796 logic_sb_block = sb_block;
799 if (!(bh = sb_bread(sb, logic_sb_block))) {
800 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
804 * Note: s_es must be initialized as soon as possible because
805 * some ext2 macro-instructions depend on its value
807 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
809 sb->s_magic = le16_to_cpu(es->s_magic);
811 if (sb->s_magic != EXT2_SUPER_MAGIC)
814 /* Set defaults before we parse the mount options */
815 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
816 if (def_mount_opts & EXT2_DEFM_DEBUG)
817 set_opt(sbi->s_mount_opt, DEBUG);
818 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
819 set_opt(sbi->s_mount_opt, GRPID);
820 if (def_mount_opts & EXT2_DEFM_UID16)
821 set_opt(sbi->s_mount_opt, NO_UID32);
822 #ifdef CONFIG_EXT2_FS_XATTR
823 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
824 set_opt(sbi->s_mount_opt, XATTR_USER);
826 #ifdef CONFIG_EXT2_FS_POSIX_ACL
827 if (def_mount_opts & EXT2_DEFM_ACL)
828 set_opt(sbi->s_mount_opt, POSIX_ACL);
831 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
832 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
833 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
834 set_opt(sbi->s_mount_opt, ERRORS_CONT);
836 set_opt(sbi->s_mount_opt, ERRORS_RO);
838 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
839 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
841 set_opt(sbi->s_mount_opt, RESERVATION);
843 if (!parse_options((char *) data, sb))
846 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
847 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
850 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
851 EXT2_MOUNT_XIP if not */
853 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
854 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
855 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
856 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
857 ext2_msg(sb, KERN_WARNING,
858 "warning: feature flags set on rev 0 fs, "
859 "running e2fsck is recommended");
861 * Check feature flags regardless of the revision level, since we
862 * previously didn't change the revision level when setting the flags,
863 * so there is a chance incompat flags are set on a rev 0 filesystem.
865 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
867 ext2_msg(sb, KERN_ERR, "error: couldn't mount because of "
868 "unsupported optional features (%x)",
869 le32_to_cpu(features));
872 if (!(sb->s_flags & MS_RDONLY) &&
873 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
874 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
875 "unsupported optional features (%x)",
876 le32_to_cpu(features));
880 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
882 if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
884 ext2_msg(sb, KERN_ERR,
885 "error: unsupported blocksize for xip");
889 /* If the blocksize doesn't match, re-read the thing.. */
890 if (sb->s_blocksize != blocksize) {
893 if (!sb_set_blocksize(sb, blocksize)) {
894 ext2_msg(sb, KERN_ERR, "error: blocksize is too small");
898 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
899 offset = (sb_block*BLOCK_SIZE) % blocksize;
900 bh = sb_bread(sb, logic_sb_block);
902 ext2_msg(sb, KERN_ERR, "error: couldn't read"
903 "superblock on 2nd try");
906 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
908 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
909 ext2_msg(sb, KERN_ERR, "error: magic mismatch");
914 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
916 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
917 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
918 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
920 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
921 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
922 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
923 !is_power_of_2(sbi->s_inode_size) ||
924 (sbi->s_inode_size > blocksize)) {
925 ext2_msg(sb, KERN_ERR,
926 "error: unsupported inode size: %d",
932 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
933 le32_to_cpu(es->s_log_frag_size);
934 if (sbi->s_frag_size == 0)
936 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
938 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
939 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
940 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
942 if (EXT2_INODE_SIZE(sb) == 0)
944 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
945 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
947 sbi->s_itb_per_group = sbi->s_inodes_per_group /
948 sbi->s_inodes_per_block;
949 sbi->s_desc_per_block = sb->s_blocksize /
950 sizeof (struct ext2_group_desc);
952 sbi->s_mount_state = le16_to_cpu(es->s_state);
953 sbi->s_addr_per_block_bits =
954 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
955 sbi->s_desc_per_block_bits =
956 ilog2 (EXT2_DESC_PER_BLOCK(sb));
958 if (sb->s_magic != EXT2_SUPER_MAGIC)
961 if (sb->s_blocksize != bh->b_size) {
963 ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
967 if (sb->s_blocksize != sbi->s_frag_size) {
968 ext2_msg(sb, KERN_ERR,
969 "error: fragsize %lu != blocksize %lu"
970 "(not supported yet)",
971 sbi->s_frag_size, sb->s_blocksize);
975 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
976 ext2_msg(sb, KERN_ERR,
977 "error: #blocks per group too big: %lu",
978 sbi->s_blocks_per_group);
981 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
982 ext2_msg(sb, KERN_ERR,
983 "error: #fragments per group too big: %lu",
984 sbi->s_frags_per_group);
987 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
988 ext2_msg(sb, KERN_ERR,
989 "error: #inodes per group too big: %lu",
990 sbi->s_inodes_per_group);
994 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
996 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
997 le32_to_cpu(es->s_first_data_block) - 1)
998 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
999 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1000 EXT2_DESC_PER_BLOCK(sb);
1001 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1002 if (sbi->s_group_desc == NULL) {
1003 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1006 bgl_lock_init(sbi->s_blockgroup_lock);
1007 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1008 if (!sbi->s_debts) {
1009 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1010 goto failed_mount_group_desc;
1012 for (i = 0; i < db_count; i++) {
1013 block = descriptor_loc(sb, logic_sb_block, i);
1014 sbi->s_group_desc[i] = sb_bread(sb, block);
1015 if (!sbi->s_group_desc[i]) {
1016 for (j = 0; j < i; j++)
1017 brelse (sbi->s_group_desc[j]);
1018 ext2_msg(sb, KERN_ERR,
1019 "error: unable to read group descriptors");
1020 goto failed_mount_group_desc;
1023 if (!ext2_check_descriptors (sb)) {
1024 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1027 sbi->s_gdb_count = db_count;
1028 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1029 spin_lock_init(&sbi->s_next_gen_lock);
1031 /* per fileystem reservation list head & lock */
1032 spin_lock_init(&sbi->s_rsv_window_lock);
1033 sbi->s_rsv_window_root = RB_ROOT;
1035 * Add a single, static dummy reservation to the start of the
1036 * reservation window list --- it gives us a placeholder for
1037 * append-at-start-of-list which makes the allocation logic
1040 sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1041 sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1042 sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1043 sbi->s_rsv_window_head.rsv_goal_size = 0;
1044 ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1046 err = percpu_counter_init(&sbi->s_freeblocks_counter,
1047 ext2_count_free_blocks(sb));
1049 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1050 ext2_count_free_inodes(sb));
1053 err = percpu_counter_init(&sbi->s_dirs_counter,
1054 ext2_count_dirs(sb));
1057 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1061 * set up enough so that it can read an inode
1063 sb->s_op = &ext2_sops;
1064 sb->s_export_op = &ext2_export_ops;
1065 sb->s_xattr = ext2_xattr_handlers;
1066 root = ext2_iget(sb, EXT2_ROOT_INO);
1068 ret = PTR_ERR(root);
1071 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1073 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1077 sb->s_root = d_alloc_root(root);
1080 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1084 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1085 ext2_msg(sb, KERN_WARNING,
1086 "warning: mounting ext3 filesystem as ext2");
1087 if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1088 sb->s_flags |= MS_RDONLY;
1089 ext2_write_super(sb);
1094 ext2_msg(sb, KERN_ERR,
1095 "error: can't find an ext2 filesystem on dev %s.",
1099 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1100 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1101 percpu_counter_destroy(&sbi->s_dirs_counter);
1103 for (i = 0; i < db_count; i++)
1104 brelse(sbi->s_group_desc[i]);
1105 failed_mount_group_desc:
1106 kfree(sbi->s_group_desc);
1107 kfree(sbi->s_debts);
1111 sb->s_fs_info = NULL;
1112 kfree(sbi->s_blockgroup_lock);
1117 static void ext2_clear_super_error(struct super_block *sb)
1119 struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1121 if (buffer_write_io_error(sbh)) {
1123 * Oh, dear. A previous attempt to write the
1124 * superblock failed. This could happen because the
1125 * USB device was yanked out. Or it could happen to
1126 * be a transient write error and maybe the block will
1127 * be remapped. Nothing we can do but to retry the
1128 * write and hope for the best.
1130 ext2_msg(sb, KERN_ERR,
1131 "previous I/O error to superblock detected\n");
1132 clear_buffer_write_io_error(sbh);
1133 set_buffer_uptodate(sbh);
1137 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1140 ext2_clear_super_error(sb);
1141 spin_lock(&EXT2_SB(sb)->s_lock);
1142 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1143 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1144 es->s_wtime = cpu_to_le32(get_seconds());
1145 /* unlock before we do IO */
1146 spin_unlock(&EXT2_SB(sb)->s_lock);
1147 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1149 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1154 * In the second extended file system, it is not necessary to
1155 * write the super block since we use a mapping of the
1156 * disk super block in a buffer.
1158 * However, this function is still used to set the fs valid
1159 * flags to 0. We need to set this flag to 0 since the fs
1160 * may have been checked while mounted and e2fsck may have
1161 * set s_state to EXT2_VALID_FS after some corrections.
1163 static int ext2_sync_fs(struct super_block *sb, int wait)
1165 struct ext2_sb_info *sbi = EXT2_SB(sb);
1166 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1168 spin_lock(&sbi->s_lock);
1169 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1170 ext2_debug("setting valid to 0\n");
1171 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1173 spin_unlock(&sbi->s_lock);
1174 ext2_sync_super(sb, es, wait);
1179 void ext2_write_super(struct super_block *sb)
1181 if (!(sb->s_flags & MS_RDONLY))
1182 ext2_sync_fs(sb, 1);
1187 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1189 struct ext2_sb_info * sbi = EXT2_SB(sb);
1190 struct ext2_super_block * es;
1191 unsigned long old_mount_opt = sbi->s_mount_opt;
1192 struct ext2_mount_options old_opts;
1193 unsigned long old_sb_flags;
1196 spin_lock(&sbi->s_lock);
1198 /* Store the old options */
1199 old_sb_flags = sb->s_flags;
1200 old_opts.s_mount_opt = sbi->s_mount_opt;
1201 old_opts.s_resuid = sbi->s_resuid;
1202 old_opts.s_resgid = sbi->s_resgid;
1205 * Allow the "check" option to be passed as a remount option.
1207 if (!parse_options(data, sb)) {
1212 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1213 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1215 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1216 EXT2_MOUNT_XIP if not */
1218 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1219 ext2_msg(sb, KERN_WARNING,
1220 "warning: unsupported blocksize for xip");
1226 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1227 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1228 invalidate_inodes(sb)) {
1229 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1230 "xip flag with busy inodes while remounting");
1231 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1232 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1234 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1235 spin_unlock(&sbi->s_lock);
1238 if (*flags & MS_RDONLY) {
1239 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1240 !(sbi->s_mount_state & EXT2_VALID_FS)) {
1241 spin_unlock(&sbi->s_lock);
1246 * OK, we are remounting a valid rw partition rdonly, so set
1247 * the rdonly flag and then mark the partition as valid again.
1249 es->s_state = cpu_to_le16(sbi->s_mount_state);
1250 es->s_mtime = cpu_to_le32(get_seconds());
1251 spin_unlock(&sbi->s_lock);
1253 err = vfs_dq_off(sb, 1);
1254 if (err < 0 && err != -ENOSYS) {
1256 spin_lock(&sbi->s_lock);
1260 ext2_sync_super(sb, es, 1);
1262 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1263 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1265 ext2_msg(sb, KERN_WARNING,
1266 "warning: couldn't remount RDWR because of "
1267 "unsupported optional features (%x).",
1273 * Mounting a RDONLY partition read-write, so reread and
1274 * store the current valid flag. (It may have been changed
1275 * by e2fsck since we originally mounted the partition.)
1277 sbi->s_mount_state = le16_to_cpu(es->s_state);
1278 if (!ext2_setup_super (sb, es, 0))
1279 sb->s_flags &= ~MS_RDONLY;
1280 spin_unlock(&sbi->s_lock);
1282 ext2_write_super(sb);
1284 vfs_dq_quota_on_remount(sb);
1289 sbi->s_mount_opt = old_opts.s_mount_opt;
1290 sbi->s_resuid = old_opts.s_resuid;
1291 sbi->s_resgid = old_opts.s_resgid;
1292 sb->s_flags = old_sb_flags;
1293 spin_unlock(&sbi->s_lock);
1297 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1299 struct super_block *sb = dentry->d_sb;
1300 struct ext2_sb_info *sbi = EXT2_SB(sb);
1301 struct ext2_super_block *es = sbi->s_es;
1304 spin_lock(&sbi->s_lock);
1306 if (test_opt (sb, MINIX_DF))
1307 sbi->s_overhead_last = 0;
1308 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1309 unsigned long i, overhead = 0;
1313 * Compute the overhead (FS structures). This is constant
1314 * for a given filesystem unless the number of block groups
1315 * changes so we cache the previous value until it does.
1319 * All of the blocks before first_data_block are
1322 overhead = le32_to_cpu(es->s_first_data_block);
1325 * Add the overhead attributed to the superblock and
1326 * block group descriptors. If the sparse superblocks
1327 * feature is turned on, then not all groups have this.
1329 for (i = 0; i < sbi->s_groups_count; i++)
1330 overhead += ext2_bg_has_super(sb, i) +
1331 ext2_bg_num_gdb(sb, i);
1334 * Every block group has an inode bitmap, a block
1335 * bitmap, and an inode table.
1337 overhead += (sbi->s_groups_count *
1338 (2 + sbi->s_itb_per_group));
1339 sbi->s_overhead_last = overhead;
1341 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1344 buf->f_type = EXT2_SUPER_MAGIC;
1345 buf->f_bsize = sb->s_blocksize;
1346 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1347 buf->f_bfree = ext2_count_free_blocks(sb);
1348 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1349 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1350 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1352 buf->f_files = le32_to_cpu(es->s_inodes_count);
1353 buf->f_ffree = ext2_count_free_inodes(sb);
1354 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1355 buf->f_namelen = EXT2_NAME_LEN;
1356 fsid = le64_to_cpup((void *)es->s_uuid) ^
1357 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1358 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1359 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1360 spin_unlock(&sbi->s_lock);
1364 static int ext2_get_sb(struct file_system_type *fs_type,
1365 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1367 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1372 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1373 * acquiring the locks... As quota files are never truncated and quota code
1374 * itself serializes the operations (and noone else should touch the files)
1375 * we don't have to be afraid of races */
1376 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1377 size_t len, loff_t off)
1379 struct inode *inode = sb_dqopt(sb)->files[type];
1380 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1382 int offset = off & (sb->s_blocksize - 1);
1385 struct buffer_head tmp_bh;
1386 struct buffer_head *bh;
1387 loff_t i_size = i_size_read(inode);
1391 if (off+len > i_size)
1394 while (toread > 0) {
1395 tocopy = sb->s_blocksize - offset < toread ?
1396 sb->s_blocksize - offset : toread;
1399 tmp_bh.b_size = sb->s_blocksize;
1400 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1403 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1404 memset(data, 0, tocopy);
1406 bh = sb_bread(sb, tmp_bh.b_blocknr);
1409 memcpy(data, bh->b_data+offset, tocopy);
1420 /* Write to quotafile */
1421 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1422 const char *data, size_t len, loff_t off)
1424 struct inode *inode = sb_dqopt(sb)->files[type];
1425 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1427 int offset = off & (sb->s_blocksize - 1);
1429 size_t towrite = len;
1430 struct buffer_head tmp_bh;
1431 struct buffer_head *bh;
1433 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1434 while (towrite > 0) {
1435 tocopy = sb->s_blocksize - offset < towrite ?
1436 sb->s_blocksize - offset : towrite;
1439 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1442 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1443 bh = sb_bread(sb, tmp_bh.b_blocknr);
1445 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1451 memcpy(bh->b_data+offset, data, tocopy);
1452 flush_dcache_page(bh->b_page);
1453 set_buffer_uptodate(bh);
1454 mark_buffer_dirty(bh);
1463 if (len == towrite) {
1464 mutex_unlock(&inode->i_mutex);
1467 if (inode->i_size < off+len-towrite)
1468 i_size_write(inode, off+len-towrite);
1470 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1471 mark_inode_dirty(inode);
1472 mutex_unlock(&inode->i_mutex);
1473 return len - towrite;
1478 static struct file_system_type ext2_fs_type = {
1479 .owner = THIS_MODULE,
1481 .get_sb = ext2_get_sb,
1482 .kill_sb = kill_block_super,
1483 .fs_flags = FS_REQUIRES_DEV,
1486 static int __init init_ext2_fs(void)
1488 int err = init_ext2_xattr();
1491 err = init_inodecache();
1494 err = register_filesystem(&ext2_fs_type);
1499 destroy_inodecache();
1505 static void __exit exit_ext2_fs(void)
1507 unregister_filesystem(&ext2_fs_type);
1508 destroy_inodecache();
1512 module_init(init_ext2_fs)
1513 module_exit(exit_ext2_fs)